Fibroids, tumors and other tissue masses are often treated by ablation. In many cases, local ablation of the diseased tissue is carried out by inserting a therapeutic device into the tissue and carrying out therapeutic activity designed to destroy the diseased cells. For example, electrical energy may be applied to the affected area by placing one or more electrodes into the affected tissue and discharging electric current therefrom to ablate the tissue. Alternatively, tissue may be ablated cryogenically, by applying heat or chemically by injecting fluids with appropriate properties to the target tissue.
However, as many tumors and fibroids are loosely held in place by ligaments and other structures, movement of the target tissue mass may make it difficult to insert a needle electrode or other energy delivery device thereinto. Grasping devices and anchors may be used to immobilize the target tissue mass while an electrode is inserted thereinto, but these procedures add more complexity to the operation and may require additional incisions. The surgeon may also require assistance from additional personnel to carry out such procedures.
RF ablation procedures also benefit from visualization methods used to correctly position the electrodes within the target tissue mass and to determine the effectiveness of treatment. A degree of visualization may be obtained by inserting the ablation device into the vicinity of the target tissue mass using an endoscopic instrument with a vision system. However, the field of view of these vision systems is small and may be insufficient to properly perform and assess the effectiveness of the treatment. Conventional vision systems may also have difficulty in facilitating the positioning of the electrodes within the tissue, as the tissue itself obscures viewing of the electrodes.